Marlin 60 Trigger Job Made Easy

There is something special about the Marlin 60. In 2010, Marlin Firearms proudly celebrates 50 years of non-stop success with this 22 autoloader. Is it still going to be successful when it hits 100 years old like the 1911? What is in the essence of its huge popularity? When I think of the reasons why I like this rifle, the three major features that come to mind are convenience, accuracy and price.

It is convenient because it has a capacity of 14 rounds in the tubular magazine (older models held up to 18 rounds) and the loading is easy. Further, it does not require separate detachable magazine which may be lost or damaged. Finally, it has a bolt hold open function when the last round is fired, making the now-empty rifle easier to inspect in the chamber. Marlin 60s tend to be accurate right from the shelf because of the micro-groove rifl ing.

This rifl ing has multiple but shallow grooves which do not damage the bullet as much as the other types of deeper rifl ing. Not least important is the price. The Marlin 60 is among the most affordable .22 rifles around. Marlin 60 History The Marlin Model 99 was developed in 1959 by Ewald Nichol. Internally, it was essentially what would become the Model 60 in 1960, however, major differences are visible from the exterior.

The Model 99 featured a walnut stock and the receiver, instead of being grooved for tip-off scope mounts like the Model 60 would be, was factory-tapped to accept screw-on scope mounts. The Model 99 did not have a bolt hold-open device. The Model 99 was offered from 1959 through 1961. This is a stainless model with the scope installed. A lower priced version, the Model 99G, was offered under Marlin’s Glenfi eld line. The Marlin Model 60 was developed in 1960 from the Model 99 design.

The primary difference was that the stock was of birch instead of walnut to reduce production costs. Its tube magazine was a signifi cant innovation at the time for a semi-automatic .22 rifleas it featured a brass inner magazine tube. This, instead of the steel tubes often seen on earlier .22 rifles, completely eliminated the rust problems that all-steel magazines had experienced. The Model 60 additionally featured a 16-groove rifl ed barrel in Marlin’s Micro-Groove rifl ing.

This rifl ing, along with the precisioncrowned muzzle, gave the Model 60 an enhanced accuracy over competing rifles using traditional deep grooved rifl ing as the bullet was not as severely deformed while traveling down the barrel. The Model 60 has a manual bolt hold-open, activated by pushing the charging handle inward towards the gun when it is in the fully-retracted, open breech position.

To close the bolt with the manual bolt hold-open engaged, the charging handle must be pulled out, away from the gun, before the bolt will go forward. Since 1985, the Model 60 has also included a patented automatic last-shot bolt holdopen. This latter feature is a safety feature that locks the bolt half-way open after the last cartridge is fi red, thereby allowing the safe inspection of the now-open action. This also notifi es the user when the gun is empty.

Older Marlin Model 60s were 18 round models and with newer models being 15 rounders. The older Marlins did not have the bolt hold open feature. The 15 round model has a third screw slightly behind the trigger guard to reinforce the stock, which the old model lacks. There are a few 1985 models that were a mixture of both, 22-inch barrel, 18-round capacity, last round bolt hold open feature and the third reinforcing screw. Different wood is used for the stock itself.

The action design is a self-loading, straight blowback operation with right-side ejection. The receiver top has a serrated, non-glare finish. The receiver is held in the stock by front and rear machine screws through the forearm and the trigger guard respectively. Later models add a wood screw behind the trigger guard to reinforce the wrist of the stock. The receiver is grooved for a scope mount. For use

The sear nose, which engages the hammer notch when cocked, is inside the action and we can not see it here. without a scope, the barrel features an adjustable open rear sight and a ramp front sight. The charging handle is used to load the first round from the magazine and can be retracted and pushed in as a manual bolt hold-open feature. Current models have an automatic "last-shot" bolt hold-open device with an external lever in the front of the trigger guard to release the bolt.

All versions have an easily accessible cross-bolt safety located above the trigger. When disassembled, the trigger guard with trigger and safety remains in the stock. Marlin uses their proprietary Micro-Groove rifl ing in the Model 60. The twist rate is 1:16 inches, righthand. Micro-Groove rifl ing uses 16 small lands and grooves rather than 4, 6 or 8 deeper grooves used in most rifles. This increases the accuracy of the rifle by lessening deformation of fi red bullets traveling down the barrel.

Although the Model 60 is one of the least expensive .22 semi-automatic rifles sold, it has the reputation of being one of the most accurate. Unlike some competing .22 semiautomatic rifles, such as the Ruger 10/22, there are relatively few aftermarket accessories sold for the utilitarian Model 60. Despite this, it has been sold in over thirty-fi ve variants, and is one of the fastest-selling rifles ever.

While earlier .22 semiautomatic rifles were often designed to function with .22 Short, .22 Long and .22 Long Rifle interchangeably, the Model 60 is optimized for the .22 Long Rifle cartridge only. Marlin reports that more than 11 million of these rifles have been manufactured in the past 50 years with 35 The gun is placed into the vise of the milling machine with the action completely assembled and attached to a receiver. Only the stock and scope need to be taken off.

This is a precision operation, which should remove as less material as possible. variants available. I am not going to continue the list of Marlin 60’s advantages as there are other publications dedicated to that. Instead, I am going to concentrate on certain disadvantages and gunsmithing, particularly on the trigger job. As it happens with any popular firearm, owners bring them to a gunsmith with custom requirements.

Customization is not a repair of a malfunction but providing a gun with some features increasing convenience and comfort of its usage by a particular customer beyond the base model. Some of these customizations, such

This screw is 6×48 and headless. The tail of the screw should not extend beyond the trigger guard. as shortening the stock, refinishing or installing a scope are straightforward and easy to provide. With Marlin 60 the single most typically requested customization is a trigger job. That isn’t surprising as stock Marlin 60s often have hard, creepy trigger pulls with a signifi cant overtravel.

Well, that is why any trigger job would be requested, but the problem here is that the design of this gun makes the trigger job awkward and time consuming. A qualifi ed gunsmith doing this job in traditional manner would likely put up a bill for this exceeding the cost of the rifle itself. This is why some gunsmiths would not take this job as few customers would justify the expense. Trigger Job To better understand the described contradiction let’s first recall what a traditional trigger job is.

In a case when the trigger mechanism is not adjustable, that is, not factory-equipped with adjustments for trigger pull tension, length of travel and over-travel, the trigger job consists of two steps. The first step is honing the sear nose and hammer-notch angles in order to achieve a smooth pull with desired tension. In practice, often only one of these parts is honed. Second, removing over-travel by placing a stopscrew restricting the trigger motion.

The over-travel is the motion of the trigger and trigger finger after the hammer or striker has been released from the sear. This parasite motion is happening when the bullet is still in the barrel and often is unnoticed since it coincides with the recoil. Despite its hidden nature over-travel can effect the point of impact by moving the gun itself. The general idea of a trigger job is clear but the practical implementation of this procedure depends on the design and complexity of the trigger mechanism.

The honing of the sear and/or hammer requires removal of these parts from the action. Some actions are quite friendly in this respect. For example, the hammer of 1911 type pistol can be removed by driving out two pins; some other guns have dropdown trigger mechanisms which also simplifi es access to the hammer and sear. Unfortunately, this is not the case with Marlin 60.

All moving parts of this rifle are assembled between two parallel plates and for taking out the hammer or sear we need to disassemble the whole action. A one time disassembly of a notso-friendly mechanism isn’t too diffi cult but a trigger job is a trial and error process. After initial honing of the hammer notch and sear the action has to be assembled and the trigger pull tested for smoothness and pulltension.

Consider that with the Marlin design a partial assembly would not work since several springs are affecting the trigger pull and have to be in place for the test. Besides, this test should be done with the trigger and on this rifle the trigger is apart of the stock, thus completely separated from the action when stock is taken off. The typical trigger job normally requires several iterations and this unfriendly will be disassembled and assembled multiple times.

This is when you start wondering where exactly the joy of gunsmithing is. Catheterization, Not Surgery Using medical terms in the sub head like this may seem over the top but this sums up my suggestions for performing a Marlin 60 trigger job. The advantage of this approach is that there is no need for disassembling the action at all, making the intermediate trials of the trigger pull quite easy. Note the location of the sear and hammer in the accompanying photos.

The sear nose, which engages the hammer notch when cocked, is inside the action and we do not see it. Much more easily accessible is the hammer notch. Despite its close location we cannot do fine honing and polishing of this notch through the vertical approach to it. The reason is that the hammer notch has to be honed along the edges rather than across.

However, if we had access to these parts from the side allowing us to use a proper fi le or stone we would be able to do this job without disassembling the action and removing the hammer. This required access is easily provided by milling a small hole in the side plate of the ac-

tion. The location of this hole should be carefully selected to provide a suffi cient space for moving the fi le along the hammer notch. The action can be secured in the milling machine between wooden blocks without need to remove the mechanism from the receiver. Only the scope and the stock are removed. For this project I have decided to do the trigger job by honing only the hammer notch while leaving the sear as is.

In case the sear also required some honing, I would mill another hole where the sear nose is located. I need to stress that milling of the access hole requires attention. The cutter should stop right after penetrating the side plate, otherwise, it would damage internal parts. Once access to the notch is made the honing is just a usual trigger job process. I think the best tool for this job is afine diamond needle fi le since the hammer is hardened and access is limited for a proper stone.

Some caution needs to be exercised. Removing too much metal from the notch or providing wrong angle would end up with the hammer releasing from the sear after cocking. The trigger pull also should not be dangerously light. The best pull weight is probably between 3 and 3.5 pounds. Notice that this approach to a trigger job allows for frequent trials of the trigger pull since no disassembly has been done.

Trigger Overtravel Screw After achieving a smooth and nice trigger pull we have to take care of the trigger over-travel. Our intention should be to stop trigger travel as soon as the hammer slips from the sear. That would impede motion of the trigger, finger and the gun itself while the bullet is still in the barrel. In general it is normally done by placing the stop screw somewhere in the trigger group, in the trigger itself or the trigger guard. Different guns may require different approaches.

In the case of Marlin 60 the best place for this screw I can find is on the trigger guard. I used a headless 6×48 screw installed in the trigger guard and prepared for the adjustment. Before the adjustment you will need to install the stock with the trigger. The adjustment of the stop-screw is done in the following steps: 1. Drill the trigger guard and thread it for the selected screw. 2. Put the stock on. 3. Cock the hammer by pulling the bolt back and releasing. 4.

Turn the stop-screw far enough to block the release of the hammer. In other words, screw should stop the trigger before it releases the hammer from the sear. 5. While keeping the trigger pulled and seated tight on the stopscrew, slowly undo the stop-screw until the hammer drops from the sear. Stop rotating the screw. 6. Measure the part of the screw extending beyond the trigger guard. Unscrew stop-screw from the trigger guard and cut the front of it by the length extending beyond the trigger guard.

Chamfer the cut. 7. Put the stop-screw back into the trigger guard using thread-locker and repeat the steps 1-3. 8. Undo the stop screw 1/4 of a turn more after the hammer drops to enable proper trigger function conditions of changing temperature and mechanical fluctuations. 9. Make sure that the screw does not extend beyond the trigger guard after the fi nal adjustment. Conclusions A trigger job on Marlin 60 is considered difficult because the action is a pain to work with.

In this article I’ve described an alternative approach to accomplishing this which avoids disassembly completely by making access to the hammer notch through the action side-plate by milling a slot and by adding a trigger overtravel screw to the trigger guard. A good trigger job on any rifle is an important practical matter since allows it allows for full utilization of the potential accuracy. AG American Gunsmithing Association